1. Field of the Invention:
The present invention relates to an implement and, more particularly, to such an earth working implement which obviates many of the difficulties associated with the use of conventional earth working devices.
2. Description of the Prior Art:
The prior art relative to earth working implements is replete with a multiplicity of devices broadly intended to perform the same operational objectives. The scope of this prior art is indicative of the fact that conventional devices have been less than completely successful in achieving these operational objectives. For example, the Willis U.S. Pat. No. 1,245,295 issued in 1917 discloses a device which is closely similar in structure and overall operation to the device disclosed by the Anderson et al. U.S. Pat. No. 4,423,789 issued in 1984. Both of these patents are directed to a device which has a center disc gang assembly extending to what can be defined as a full, operative width. There is a front gang assembly which extends laterally to engage approximately the left half of the swath traversed by the device and a rear gang assembly which extends laterally to engage approximately to the right half of the swath traversed by the device. The front and rear gang assemblies are individually disposed along substantially parallel longitudinal axes while the central gang assembly is disposed at an acute angle relative thereto. The disc blades of the central gang assembly are operable to turn the soil to the right relative to the path of travel while the disc blades of the front and rear gang assemblies are adapted to turn the soil to the left relative to the path of travel, but from opposite sides of the longitudinal axis of the device.
The deficiencies inherent in such prior devices can readily be identified by those familiar with their rise, but may not be readily apparent simply upon examination of the devices by those unfamiliar with their operation. Such devices, of course, turn or otherwise disturb the soil within a swath of contact. The broad operational objectives for doing so include the control of plant growth; the improvement of drainage; preparation of the soil for further manipulation such as, for example, the formation of furrows for purposes of irrigation; aesthetic enhancement and the like; and any combination of these broad purposes. In general, the effectiveness of the devices in achieving these objectives may be determined by evaluation relative to several well recognized criteria.
A first criterion is that the soil be worked at depth rather than by means simply of superficial contact. If the soil is not worked thoroughly to a depth well beneath the surface, nothing more than perhaps a cosmetic result is achieved. Without turning of the soil through the medium of the concave disc blades, little or no benefit is attained. For example, unwanted plant life, such as weeds, should preferably be buried beneath a layer of soil so as to accelerate its decomposition while enriching the soil. Similarly, unless the soil is turned, the soil cannot be aerated to any beneficial depth. More importantly in the case of hardened earth, or earth which has not frequently been worked, or earth which contains substantial incursions of rock, hardpan or the like, the soil cannot be reduced to the desired consistency without being worked to an adequate depth. Conventional devices may simply pass over the surface of the earth without any significant penetration and with little beneficial result.
A second criterion is that the soil be worked as thoroughly and evenly as possible so as to be converted to a substantially uniform consistency. This facilitates the subsequent use of the soil, whether for the planting of a new crop, weed control, the subsequent reworking of the soil, or the like. To the extent the soil is not of a substantially uniform consistency, the resulting soil condition may be inadequate for the purposes intended.
A third criterion is that, to the extent possible, the soil after such working be returned to a grade and distribution desired. In normal farming operations, this is a substantially ambient condition. It is desired that the soil is simply worked and then returned to is original grade and distribution. Of course, if subsequent working of the soil is to be performed, such as in the formation of furrows for irrigation or where a land levelling operation is to follow, this may not be as significant. However, in most applications, the optimum result from a single pass with such a device is to turn the soil deeply and thoroughly, as previously noted, and then to return the soil to its ambient grade and distribution so that no further working of the soil is required to achieve this result.
A fourth criterion is that the device itself be readily and dependably adjustable to a multiplicity of adjusted settings for optimum performance of the desired task. This is important in order to permit the device to be adjusted for the particular width of the swath desired, to be able to adjust for the condition of the soil being turned, to be able to adjust for the grade of the ambient soil as well as to permit adjustment for such other variables as the power of the tractor pulling the implement, the topography of the area, and the like.
The prior art, when evaluated against these and other criteria, is deficient in nearly every instance to one degree or another. While some prior art devices may be more effective relative to certain of the criteria, in other respects they are frequently less effective.
Therefore, it has long been known that it would be desirable to have an earth working device which obviates the difficulties associated with the use of conventional earth working equipment; which is operable dependably to work the soil at depth during use thereof; which works the soil thoroughly and evenly to convert the soil to a substantially uniform consistency during a single pass; which returns the soil substantially to its ambient grade and distribution; which is dependably and readily adjusted to particular working configurations; and which is otherwise entirely effective in achieving its desired operational objectives.